Screen



J. L. LEE.

SCREEN.

APPLICATION FILED MAR. n, 1916.

3 Patented Aug. 1, 1916.

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J. L. LEE.

SCREEN.

APPLICATION FILED MAR. 11. 1916.

Paterited Aug. 1,1916.

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JOSEPH L. LEE, OF CARBONDALE, PENNSYLVANIA.

SCREEN.

Specification of Letters Patent.

Patented Aug. 1, 19316.

Application filed March 11, 1916. Serial No. 83,462.

To all whom it may concern:

Be it known that I, JOSEPH L. LEE, a citi' zen of the United States,residing at Garbondale, in the county of Lackawanna and State ofPennsylvania, have invented certain new and useful Improvements inScreens, of which the following is a specification, reference being hadto the accompanying drawings.

This invention relates to sectional screens for sifting coal and othersubstances.

The objects accomplished are the production of enlarged screeningsurface without increasing the size of the screen, combined with greaterstiffness and efficiency of the screen.

The particular features of the invention will be further describedhereinafter.

The drawings show my improved sections and screen constructed therefrom.

Figure 1 is a perspective view of a screen plate or section. Fig. 2 is atop view of screen comprising several plates or sections securedtogether. Fig. 8 is a sectional side view through the line w-m of Fig.2. Fig. 4c shows a screen made up of sections provided with wideningslots instead of circular perforations, and Fig. 5 shows a side view ofthe screen constructed with spacing washers between the plates.

In the drawings A represents my improved form and construction of screenplates or sections which are each made up separately, and may be securedtogether to form a screen of the desired dimensions. These plates orsections are made of sheet metal of any desired thickness and may be ofvarious dimensions. The length of the individual plate is usually thewidth of a screen made up of several plates. Each plate has a main bodyportion which has perforations or openings a, a distributed over it andplain marginal edges 2), 6 g, g, which are provided with small holes z',i, to facilitate its being bolted or riveted to an adjoining plate or toa frame. The holes 2', in the margins Z) and Z2 are made so they willregister one over the other when two plates are superimposed for thepurpose of be1ng joined together. Near one of its edges the perforatedportion of the plate A is turned under until it forms substantially asemicircle 0, care being taken that the nonperforated portion B formingone margin of the plate, will be flat and even with the perforated faceof the main body of the plate above it. By this means the blank margin 6of the plate is brought underneath its perforated portion and the twomargins b and b of the plate will have parallel edges and terminate inthe same direction. The diameter of the semi-circle 0, will determinethe depth of the lip or height of the upper face of one plate above theadjoining one, upon which it rests, and may be varied to suit the sizeor style of screen desired.

In making up a screen, of more than one section the plates are laidtogether so that the straight fiat margin Z2 which is at the terminationof the crooked portion, or semicircle, and located under one plate,rests on the straight fiat margin 6 of an adjoining plate. Rivets orbolts it, it, may then be passed through the registering holes 2', z, inthe edges of both plates, and they are firmly joined together. Theperforations in the section A, extend around the bent portion or lip 0,of the plate, so as to overlap the point of joining the plates and meetup with the perforations of the adjoining plate, thereby obtaining asectional screen with the same sifting surface as a continuous, or onepiece screen would have. By making the plate A, curved near the joiningmargin, as shown at c, and extending this form across the face of thescreen, I obtain a series of corrugations or ribs, when a screen is madeup of such plates, which greatly stiffens the struc ture and prevents itfrom-sagging at the center with the weight of the material passing overit. It will also be observed that the material being screened when itreaches the bent portion, or lip 0, will be turned or tumbled in passingto the face of the next plate or section, which increases the elii- Iusually are longer in one direction than the other and then usedlengthwise across the screen. The plates are adapted for theconstruction of screens to be used either as a shaking or stationaryscreen. In case of use in the form of a shaking screen it may be boltedon a frame which is given a reciprocating motion by cranks oreccentrics. When used as a stationary screen it should be made with thelip part of the sections downward and given sufficient incline to causethe material being screened to readily run over it. In screening coal itis sometimes desirable to provide for the separation of pieces of slatefrom the coal. The slate comes usually in flat pieces while the coal isgenerally in roundish lumps. For use in such cases the plates are joinedtogether in the manner shown in Fig. 5. v

In this construction I interpose between the plates spacing washers w,to, so the plates are separated a certain distance, and a transverseopening or slot is formed under the bent portion and a little to therear of the face of the lip 0. The bolts or rivets h, k, pass throughthe washers and the plates, securing them both in position. When thescreen is shaken or given a sidewise motion a considerable amount offiat pieces of slate will pass through these openings between theplat'es. The perforations or holes in the plates may be of any desiredshape, round, square or oblong.

In Fig. 4, I have shown the use of elongated lateral perforations mwhich are made to gradually widen as they approach the lip at thedischarge end. This form of perforation is designed to prevent thematerial from clogging the screen. The slotted perforations extend overthe face of the lip of the section and are preferably staggered, so thenarrow ends of the slots in one plate will extend under the lip of theupper adjoining plate and terminate between the wider ends of itsslots."

g It will be understood that although I have shown the plate bent intothe form of a semi-circle the material advantage to be secured is inhaving the meeting edge, or margin 6 of the plate, bent in under theperforated body of the section and alined so it will be in position torest upon, and readily fastened to the margin of an adjoinlng plate orsection. The margin 5 will be located on a plane sufliciently below theperforated body portion to allow of the rivets h, 72 being placed inposition. 'I have found the bend or crook of a semi-circle a preferableform, as it houses the lower portion of the lip or step under its upperportion and causes the metal to recede from the projected face of thelip out of the way of the material being sifted which produces a bettertumbling action of the material at this point. This form of bend alsonaturally brings the lower margin of the plate into a reversed positionalined and ready to besuperimposed on the edge of an adjacent plate; butother forms of crook or bend may be used without departing from thespirit of my invention.

Having described my invention, what I claim as new and desire to secureby Letters Patent is: i

1. A rectangular screen plate with a perforated body portion, a marginaledge along one of its sides which is on the same plane as the perforatedbody portion, the opposite side of said section having its perforatedportion bent into a semi-circle and terminat ing in a marginal edgeadapted to besuperimposed upon and secured to the marginal edge of anadjoining duplicate section substantially as shown and described.

2. A rectangular screen plate having a perforated body portion, amarginal edge along its upper side on the same plane as the bodyportion, the lower perforated part of said plate being crooked. underthe body portion and terminating in a reversed marginal edge extending.under the perforated main portion, which is alined with the uppermarginal edge and adapted to be superimposed upon and secured to theupper edge of a duplicate plate, substantially as and for the purposesshown and described.

8. A rectangular screen plate having a fiat perforated body portion, amarginal edge along one side thereof on the same plane as saidperforated body portion, a transverse curved portion along its oppositeside terminating in a reversed marginal edge on a lower plane than themain body and alined parallel with the said fiat marginal edge,substantially as and for the purposes shown and described.

4. A coal screen of the class described comprising two or morerectangular perforated sheet metal sections, the lower border portion ofeach section being bent back in a curve under the main perforated bodyportion thereof and terminating in a marginal edge which rests uponv andis bolted to a marginal edge of a continuing section, said curved borderportion of sec-' tion extending across the face of the screen andforming a stiffening corrugation substantially as shown and described.

5. A screencomprising two or more rectangular perforated plates joinedtogether along their edges and having spacing of the plates,substantially as described, and washers and slots between the edges,where spacing washers with openings between the 10 the sections aresuperimposed, substanplates where their edges are superimposed tially asshown and described. substantially as shown and described. 5 6. A screencomprising two or more rec- JOSEPH L. LEE.

tangular perforated sectional plates joined l/Vitnesses: together attheir edges having transverse JOHN MATTHEWS, raised lip formation infront of the junction C. D. BARLOW.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

. Washington, D. 0.

